P1188 - FAULT CODE - OBD2

P1188 HYUNDAI, KIA: FUEL PRESSURE MONITORING - LEAKAGE

With fuel pressure monitoring it is possible to detect leaks and other problems that the high-pressure fuel system may experience. The Engine Control Module (ECM) determines the rail pressure value, taking into account the engine driving conditions. In this action, it employs a fuel pressure regulator, which ensures that the fuel pressure reaches a required value.

The pressure in the fuel line, including the injectors and pumps, is continuously monitored during engine operation. If the rail pressure is below the required level, the regulator is closed, but if the pressure is too high, the regulator opens and part of the fuel is sent from the rail to the fuel tank.

The P1188 OBDII fault code is set by the ECM when the fuel line pressure monitoring discovers an out-of-range value, being considered by the controller as a system fault, specifically a leak.

• Check Engine light illuminated.
• The engine shuts off unexpectedly.
• Difficult to start.

The reasons for the P1188 OBD2 diagnostic code being stored are:

• The fuel filter may be in bad condition.
• A fuel injector may be defective.
• The fuel pump could be damaged.
• The Fuel Pressure Regulator (FPR) may be faulty.
• The Fuel Rail Pressure Sensor (FRP) could be in poor condition.

The corresponding steps to resolve the DTC P1188 OBDII code are:

• Consult the Technical Service Bulletins (TSB).
• Using an automotive scanner, check if there are other error codes configured. If such codes are detected, repair them according to the order shown by the scanner.
• Check the good condition of the system components such as injectors, pumps, and fuel lines. If you discover leaks or blockages in any of these, proceed with the respective corrections.
• Refer to the diagnostic steps for the Fuel Pressure Regulator and Fuel Rail Pressure Sensor. If you find inconsistencies in one of these after performing these checks, make the appropriate adjustments.